ROTADIAL: The first nanobody-based immunoassay to detect Group A Rotavirus.

ROTADIAL is a rapid nanobody (Nb)-based ELISA assay able to identify Rotavirus group A (RVA) in feces from pediatric patients. The assay is based on a sandwich of two patented llama-derived Nbs directed to the inner capsid viral protein VP6 from RVA. Nbs are directed to conformational epitopes of VP6 and recognized all human RVA strains tested, representing ideal reagents for their use in immunodiagnostic tests for RVA detection. All the steps are carried out at room temperature, bringing results in less than two hours. This assay, named ROTADIAL, was validated with a reference panel of feces from pediatric patients from Argentina. The overall sensitivity and specificity of the ROTADIAL test, when compared to a commercial test, was 100 % (100/100) and 99 % (99/100) respectively. ROTADIAL presented optimal analytical performance, being capable of detecting RVA regardless of the presence of other common human enteric infectious agents and is the first RVA-diagnostic assay developed using Nbs, worldwide.

Incomplete synapsis and chiasma localization: the chicken or the egg?

In the present study, and as a sincere tribute from the Cytogenetics teams from Madrid to Professor Máximo Drets on his 80th birthday, we have analyzed and compared 3 different grasshopper species with different synaptic patterns, a standard pattern, a second pattern with synapsis restricted to the proximal regions, and a third pattern with synapsis restricted to the distal regions. In the 3 species we have thoroughly analyzed the relationships among cohesin axis morphogenesis, formation of double strand breaks (DSBs) and recombination initiation. Our results demonstrate that in every case recombination initiation precedes synapsis, and that there is a direct relationship between the absence of meiotic recombination and the existence of particular unsynapsed chromosomal regions during prophase I. Based on our results we propose and discuss the mechanisms underlying the existence of incomplete synapsis and the localization of chiasma in wild species.

Spatio-temporal dynamics of a neutralized B chromosome in the grasshopper Eyprepocnemis plorans.

Spatial and temporal patterns of frequency variation for a neutralized B chromosome in the grasshopper Eyprepocnemis plorans were analyzed along six transects in the east of Spain to explore possible factors affecting the population dynamics of this polymorphism. Three parameters were employed to quantify B frequency: prevalence, load and mean frequency. Of them, load seemed to be the less sensitive parameter, probably due to its small range of variation. Prevalence, however, shows ample variation, but the mean frequency of B chromosomes per individual is the best parameter to characterize B frequency. Only river transects revealed significant differences among populations, and the use of two geographic explicit approaches (Mantel test and distograms) revealed significant isolation by distance (IBD), especially at the Segura River mouth, presumably due to low gene flow and drift. No temporal trend was found in the Segura River transects, which is consistent with the slow changes in B frequency expected during the random walk for neutralized B chromosomes. But these transects showed a clear spatial pattern, with B1 showing lower frequency in the upper course of this river. The present results provide the first empirical evidence of IBD in the evolution of a neutralized B chromosome, and support the notion that B dynamics at this evolutionary stage is best explained by a metapopulation approach.

[Cholestasis in pregnancy. Report of a case]. / Colestasis del embarazo. Presentación de un caso.

We present a case of Cholestasis and pregnancy that developed associated in the puerperium, to tecaluteinic ovaries and hemoperitoneum. For this reason it was necessary surgical management. We considered that it is a very unusual case so we felt interest on presenting it. To finish we would to make reference to itns possible patogenia, symptoms, and management of it.

Intermediate heterochromatic zones in Triturus (Amphibia: Caudata).

Employment of the C-banding procedure disclosed the presence of slightly stained bands in some chromosome regions of several Triturus species. These regions have been previously described in other organisms as 'grey C-bands'. Possible explanations for the presence of these bands in Triturus karyotypes are discussed.

Patterns of DNase I sensitivity in the chromosomes of the grasshopper Chorthippus parallelus (Orthoptera).

We have analysed the patterns of DNase I/nick translation in the chromosomes of the grasshopper Chorthippus parallelus erythropus. Sites of preferential DNase I-nicking were concentrated at the distal chromosome regions, thus showing the non-uniform DNase I sensitivity of different chromosome domains. Among centromeric C-bands, the heterochromatin of metacentric and acrocentric chromosomes differed with respect to their DNase I resistance.